Evaporating apparatus for recovering soda-ash.



G. H. MARSHALL.

EVAPORATING APPARATUS FOR REOOVERING SODA ASH.

APPLICATION FILED JAN. 3, 1.911- RBNEWED DEO.20,1911.

1,035,097. Patented Aug. 6, 1912.

2 SIIEBTBBKEET 1.

awumz .G. H. MARSHALL.

EVAPORATING APPARATUS FOR REGOVERING SODA ASH.

AYPI'JIDATION FILED JAN. 0,1911. RENEWED DBO.20,1911.

1,035,097. Patented Aug. 6,1912.

2 8HEETS-SHEET 2.

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lllli' @llrkitllltit PATEN FFICE.

GEORGE H. JVIARSHALL, OF NEW YORK, N. Y.

EVAPORATING APPARATUS FOR RECOVERING SODA-ASH.

Application filed January 9, 1911, Serial No. (301,674. Renewed December 20, 1911. Serial. No. 667,033. i

Specification of Letters Patent.

Patented Aug. 6, 19112.

To all whom it may concom- Be it known that l, Gnonur; H. lllw'usnann, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Evaporating Apparatus for Recovering Soda-Ash, of which the following is a specification, reference being had to the accompany-log drawings.

This invention relates to improvements in apparatus for retaining soda ash dust. the object of the invention being to provide an improved evaporator for coin-cntrating the black liquor or 'wasteliquor occasioned in the manufacture of wood pulp by the soda or sulfate processes for recovering the soda from the said waste liquor, one object of the lIlX'BlltlOll beingtoetlect improvements in the construction of the evaporating tank, and in the arrangement ot the rotary batlle elements therein, another object of the invention being to provide improved means for feeding the liquor to the evaporating tank so as to maintain the same at a constant level during the eyapca ating process.

In the accompanyin dra\vings-J igure l is a horizontal sectional View of an evaporating apparatus or concentrating apparatus constructed in accordance with my invention, the rotary ballle elements being shown in plan together with means for operating: the same. Fig. 2 is a vertical longitudinal sectional view of the same on a larger scale. Fig. 3 is a partial transverse sectional view of the same showing the improved 'tceding construction for the evaporating tank. Fig 4 is a detail elevation of one of the rotary battles. Fig. 5 is a detail transverse scctional view showing the outlet for the flow of the com-.entrated liquor from the tank.

The tank 1 which is here shown as ot 0 long rectangular form provided with an arched cover 2. A line 3. which leads directly from the rotary furnace enniloycd in the usual process of recovering soda ash is provided at one end of the tank 1, at a point above the level of the liquor therein, and from the other end of the tank, a dis charge tine -l-. extends upwardly from the arched cover. The tank is provided with a centrally disposed longitudinal vcrtical partition which tcrminatesshort of the ends oil the tank, and dividcs the. latter into two unpartment (t, 7 which are parallel with each other, tnd comn'mnicate at their ends as shown inFig. 1. A pair of longitudinally disposed shafts S extend through the compartments-t6 of the tank and are mounted in bearings at the ends of the tank and. each of these shafts is provided at. one end with spur gears 10 which are engaged by a pinion .ll of a driving shattlQ, the said drivingsha't't being here indicated as mounted in bearings 13, and provided with a fast pulley let. and a loose pulley 15 for a suitable driving belt. Hence the shafts and the ballles which they carry are rotated sinndtaneonsly and in the same direction.

The rotary battles are circular and each of them is made up of a number of segmental metal plates, the batlles being here shown as each composed ot. a pair of semi-circular segment plates 10. The said segment plates are provided at their ends and also at their centers with radially dis o-sed angle bars 17, 18 which are secured lhercto by means of rivets. These angle bars reinforce the segment plates and make the same exceedingly strong, and the end angle bars of the respective segment plates are disposed with their ontstamling webs in mutual contact as shown in Figs. 4; and (i. and dctachably secured together by means of bolts 15), so. that the segment plates may be separated from each other to enable the battles to be readily removed from their shafts, and replaced by others when the bullies become worn without the necessity of also removing the shafts or disturbing any of the other rotary bullies, each being removable from its shal'l independently of all of the others. Illach ballle is provided at its center with a hub 19 for engagement \vith'thc shaft. l lach hub is a split hub comprising a pair of semi-circular sections which are respectively secured to the respcctis segment plates of the battle by means of rivets 20. the said hub sections being; provided with radial shoulders 21 having openings through which bolts 22 extend. the said bolts coactlng with the said radial shoulders of the hub sections, to delachably secure the hub sections together, and on. the shaft, and hencewhen it is desired or becomes necessary to remove any one of thebatllers from the shaft which carries it, it is only necessary to first remove the bolts which connects its angle bars 17 together. and the bolts which connect its hub sections together as will be understood. It will also be understood that the rotary battles-arc entirely da onnectcd from one integral with the segme t plates ne haliles, and struck up there cm, by

ma ing cuts 24: in the segment plates hatlles which cuts eaten d around three sides of the Wings, the inner ends of the Wings being united as at to the segment plates.

As shown in Fig. 1, the wings of the rotary baflies in tln compartment 7 of the evaporating tank are reversed with respect to the wings of the batlles in the compartment 3, Hence the wings of the hafiies in the two compartments of the tank, owing to their slightly oblique relation to the flesvvhich marry them, and to the fact that they are on opposite sides of the baffles in the respective compartments, and the further fact that all of the said baffles rotate in the same direction, serve to set up, a slow current in the evaporaiing tank so as to cause the liquor therein to flow from end to end of the tank from one compartment thereof to the other, and in opposite directions in the said compartments as indicated by the feathered arrows in Fig. l, the direction of rotation of the bellies being indicated the unfeathered arrows. The openings in the bellies formed by striking up the wings therefrom, and the turning of the wings out the plane of the permit the passage of gases through the ballles and through the space in the evaporating rat-us above the le cl of the liquor therein. At one end of the tank on one side of the same, is a feed 26 wl icli has a longitudinally disposed vertical partition 27 forming a compartment 28 between the outer side of the said partition, and the outer side of the said feed Weir. The sup ply tank which is charged with the thin black liquor or waste liquor, occasioned in the manufacture of wood pulp by the soda or sulfate processes, is supplied to the evaporating tank by a si'litablc pump indicated 30 which is connected to the supply tank as at and the feed pife 32 of which is conncctcii to the bottom of the iced weir 26 at a point on the inner side of the parc s Luzon 2a, :1 i. or cveuloiv pipe do in;: from the pump of the coin' iaartmcnt 28 of the feed or supply weir, hack to the supply tank.

An outlet hoe: 34. is at a suitable point on the side of tank opposite that provided or supply weir, the let be being the required of tie liquor in the tank, and. an out- 36 leading from the pump of the the operation of my improved evapo rating apparatus, the rotary bailles being in motion, and the pump 30 being at Work, the said pump maintains a constant level of the black liquor in the evaporating tank,

and should the level of the liquor rise it will directly over the partition 26 in the feed or supply weir, and from thence back to the supply tank 29, through the overflow pipe Hence the overflow liquor occasioned by an excessive supply of liquor to the tank, should any such occur, Will imn1ediately return to the supply tank, back from the feeding point, and only the thick liquor containing the soda recovered by the ballles during the evaporating process will escape from the evaporating tank at the outlet 35.

The gases from the rotary furnace of the plant of which my improved evaporator forms a part, pass from the flue 3 longitudinally through the upper portion of the evapcrating tank, past the baflies and escape finally up through the flue 4. These gases strike against the balllcs and pass in tortuous paths through the openings therein. Owing to the fact that the baffles are slowly resolved Within the tank, they are alternately imersed in the liquor therein, and then presented in the paths of the soda ash dust, which is carried along by the gases. This dust is caused to adhere to the wet, upper exposed portions of the baffles, and is then dipped by the rotation of the baiiles into the liquor in. the tank, and caused to dissolve therein so that the water content of the liquor is subjected to evaporating process and carried ed with the heated gases tl A the line l, while the soda ash content oi the gases is arrested from passage j with the gases is added to the liquor in the tank as will he understood.

1, In apparatus of the class described, an e aporating tank rovided with feeding means for supplying liquor for evaporation to me a- -.k and also provided with an overflow outle at the said feeding; means, a fine forming the upper side oi the tank, {1 13618, series of rotary ballles in the tank extending from near the bottom thereof to a point above the water lineand in the line,

2. ln 1' -.'apoi'atii1g apparatus of the class described, a tank having feed weir and providml "ith a 3 trii-ition Wall and fornr in; a compartment outside of the said partition Wall, means to supply liquor the lank through the said Weir at a point on the inner side of the partition 1 means leading from the coinprutment on 0...: enter side of the partition to carry off overflow liquor from over the partition, a flue extending over and forming the upper side of the tank and a series of rotary baflles disposed in the tank and extending up into the flue.

3. ln apparatus of the class described, in combination with an evaporating tank having' a llue forming its upper side,a ted weir connuunieating with the tank and having a partition wall and an overflow eompartn'lent on the outer side of said partition wall a supply tank, a pump connected to the said supply tank to force liquor therefrom to the evaporating;- tank and communicating with the latter at a point on the inner side from the eaid overflow compartment back to the supply pipe, and ballles mounted for i l I l i i l l 4-. In apparatus of the class described, an evaporating tank having a line lornnng the upper portion thereof, means to supply liquor to and maintain the circulation of such liquor in the tank, a shaft disposed longitudinally of the tank and having its hearings therein and rotary ballles on the Hlld shaft, each hallle comprising a plate having Wing's disposed at an incline to the plane of the ballle, openings in the ballle, in

the plane thereof and covered by said wings.

In testimony whereof I hereunto allix my signature in the presence of two witnesses.

l'Vitnesses Tnos. R. H. J. T. CHASE.

GEO. H. MARSHALL.

MURPHY, 

